The Bac-to-Bac baculovirus expression system enables the efficient production of recombinant baculovirus for expression testing in insect cells. The system relies on generation of recombinant baculovirus by site-specific transposition in E. coli rather than homologous recombination in insect cells. This system features:

• Time-saving expression bacmid—With the Bac-to-Bac system, the expression cassette of the pFastBac vector recombines with the parent bacmid in DH10Bac E. coli Competent Cells to form an expression bacmid. The bacmid is then transfected into insect cells for production of recombinant baculovirus particles.

• Easy colony screening—The parent bacmid in DH10Bac E. coli contains a segment of the lacZa gene. The lacZa gene is disrupted upon transposition of the expression cassette into the bacmid, allowing for blue/white selection of recombinants for easier identification of recombinant colonies.

• High transfection efficiency with ExpiFectamine Sf Transfection Reagent—The Bac-to-Bac TOPO expression kits now come with the next-generation ExpiFectamine Sf Transfection Reagent for efficient DNA transfection in insect cells using fast, flexible protocols. Find out more about this reagent ›

• Flexibility—The Bac-to-Bac system comes with a pFastBac vector that contains a large multiple cloning site (MCS) for simplified cloning. Two additional vector formats are offered separately: pFastBac HT vector for production of histidine-tagged recombinant proteins and pFastBac Dual vector for expression of two proteins simultaneously using the p10 and polyhedrin promoters.

• High protein expression—The pFastBac vector uses the strong polyhedrin promoter to generate high levels of expression in a variety of insect cell line such as Sf9, Sf21, and High Five cells.